Adhesive tapes as capturing surfaces in Burkard sampling

Abstract

Although pressure‐sensitive adhesive tapes appear to offer many advantages over traditional adhesives in sampling with a Hirst‐type spore trap, their particle capturing efficiency has never been documented. In this paper, the particle capture efficiency of four pressure‐sensitive adhesive tapes was compared to the standard vaseline adhesive in the Burkard 7‐day volumetric spore trap. The capture efficiency was assessed at flow rates of 8 and 101 min−1 over a 16 week period with each tape run alongside the standard. Image analysis was used to count and measure the surface area of individual inorganic and organic particles collected onto each tape. Approximately 230,000 individual particles were analysed, the majority of particles collected on both standard and pressure‐sensitive adhesive tapes had a surface area less than 150 μm2 (approximately diameter 14 μm). Capture efficiency was expressed as a percentage of the counts on the standard and classified by particle size and flow rate. For particles < 1000 μm2(<36 μm in diameter), the best adhesive tape captured 247.6% at 81 min−1 and 132.5% at 101 min−1. For particles > 1000 μm2, the best adhesive tape captured 86.9% at 81 min−1 and 69.8% at 101 min−1. In addition to image analysis, manual counts of pollen grains and Alternaria‐like spore were performed over a four day period for each adhesive and parallel standard at the flow rate of 101 min−1. On the adhesive tapes, pollen grains <20 μm, and pollen grains >20 μm with heavy ornamentation and/or free standing exine elements were captured best. For the best adhesive tape, the capturing efficiency compared to the standard vaseline was 83% for all pollen grains and 60% for Alternaria‐like spores.